Silicon carbide JBS device cellular structure with novel deep groove, and preparation method thereof

Abstract

The invention discloses a silicon carbide JBS device cellular structure with a novel deep groove. The cellular structure comprises an N+ type substrate, an N- type epitaxial layer formed on the upper surface of the N+ type substrate, a groove formed above the N-type epitaxial layer, P+ type ion implantation regions located at the bottom of the groove and at the corner of the top of the groove, an N- type Schottky contact region positioned above the N-type epitaxial layer, and an N+ type ohmic contact region positioned below the substrate. The contradiction between forward conduction impedance of the device and Schottky region withstand voltage and surface electric field reliability caused by a groove structure during device design can be avoided, a transverse Schottky contact channel is added during forward conduction, and forward conduction resistance is greatly reduced; under the surge condition, the P-type contact area is increased, and the surge resistance is improved; and through multi-layer P-type injection cooperative protection, the withstand voltage of the Schottky region and the reliability of the surface electric field can be effectively improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and more specifically, the invention relates to a silicon carbide JBS device cell structure with novel deep grooves and a preparation method thereof. Background technique [0002] Wide bandgap semiconductor materials are third-generation semiconductor materials represented by materials such as silicon carbide and gallium nitride. SiC materials have developed rapidly in recent years. The SiC material has a large band gap, which can reach more than 3eV, and has excellent radiation resistance. The critical breakdown electric field can reach more than 2MV / cm. SiC material has high thermal conductivity (about 4.9W / cm.K), and the device is resistant to high temperature, which is more suitable for high-current devices than Si. Therefore, since the 1990s, power devices such as SiC MOSFETs and SBDs have been widely used in switching regulated power supplies, high-frequency heating, automotive ele...

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Problems solved by technology

The SBD structure of a single-width trench requires a compromise between the trench depth and the forward conduction resistance of the device, and a compromise between the trench spacing and the withstand voltage and surface electric field strength of the Schottky region between the trenches. , which brings contradictions to the design of high withstand voltage SBD devices

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